Stats and Prob

3 What would be the 91th percentile (P91) for such a N(0,1) distribution?

1.34

4 For a certain population diastolic blood pressure has been evaluated to have a mean value of 75, a 10th percentile (P10) of 55, an 80th percentile (P80) of 90, and a range of 60. What can we say for sure about diastolic blood pressure in that population?

Third quartile can't be more than 90.

According to a recent article in the journal "Appetite," 70% of 2 to 5 year old children living in the US suffer from food neophobia. We choose at random five 2 to 5 year old children living in the US.

5 What is the probability that at least four of the chosen children suffer from food neophobia?

0.528

6 What is the probability that the number of children suffering from food neophobia among the five chosen is between one and three, both inclusive?

0.6

According to a recent article in the journal "Environmental Health Perspectives," the amount of soil ingested in one day by infants living in a particular town is a random variable with a normal distribution with mean 20 g and variance 4. Assume that is really the case.

7 What is the probability that an infant chosen at random from that town will ingest more than 25 grams of soil in one day?

0.8944

8 What is the probability that an infant chosen at random from that town will ingest less than 15 grams of soil in one day?

0.9876

9 Now assume that we chose at random 4 infants from that town. What is the probability that none of them will ingest more than 25 grams of soil in one day?

0.9754

10 Suppose we flip a fair coin 10 times. What is the probability that we will get heads every single time? 0.001

11 Now suppose we flip a coin that has heads on both sides. What is now the probability that we will get heads every single time? 1, obviously.

A clinic has four departments, headed by doctor A, doctor B, doctor C, and doctor D, respectively. Dr. A's department is treating 10 patients at this time, Dr. B's department is treating 2 patients, Dr. C's department is treating 5 patients, and Dr. D's department is treating 4 patients. A patient from the clinic is chosen to be entered in a new clinical trial after informed consent. The procedure to choose such a patient is the following: first a department in the clinic is chosen at random, and then a patient from the chosen department is chosen also at random.

12 What is the probability that John R, a patient treated by Dr. C, will be chosen to enter the clinical trial? 0.05

13 What is the probability that Mary H., a patient in Dr. A's department, will be chosen to enter the clinical trial?

0.025

One or two might be wrong so I need someone to check them. Reviewing for the final exam (our prof. gave me many pages like this). Thank-you in advance.

Re: Stats and Prob

Re: Stats and Prob

5 is correct and 6 is incorrect. I will check the others.

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Stats and Prob

8, too.

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Stats and Prob

Re: Stats and Prob

12 and 13 are correct!

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Stats and Prob

Hm? There is only one onswer for 6.

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Stats and Prob

Re: Stats and Prob

3 is correct.

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.

Re: Stats and Prob

The exact answer for 6 is 0.46935 .

Here lies the reader who will never open this book. He is forever dead.Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and PunishmentThe knowledge of some things as a function of age is a delta function.